Dye-resistant coating composition



E. C. ATWELL vDYE-RESISV'I'AN'I COATING COMPOSITION March 16, 19.43.

Filed Feb. 10,` 1958 Patented Mar. 16, 194.?.l

DYE-RESISTANT OOATING COMPOSITION Emea c. Arwen, Cranston, a. I.. minor u stlantic Rayon Comration, Providence, B. I., a corporation of Rhode Island Application February 10, 1938, Serial No. 189,795

2 Claims. '(Cl. 26o-20);

-This invention relates. to a physically and chemically resistant composition for impregnating and/or coating surfaces and to a method for the preparation and application of the same.

`Sonie surfaces to which a coating is to be applied are neither soft nor rigid, but more or less resilient. With such surfaces or materials, it is necessary that the coating compositions applied to them shall be capable of exhibiting at least the same or a greater degree of resiliency than the surface of the body material, especially when the coated surface is to be subjected to flexing. In such cases, the adhesion of the coating to the surface must also be capable of withstanding the stresses and strains set up between them by the flexion of the composite surface coating layer. 'Ihe coating must also be strong or tough enough to withstand the lateral tensions or compressions transmitted throughout its surface when under such strains without disruption of its structural continuity.

On the other hand, it is desirable that the coating, after having been applied, should set to a rm, or even hard but resilient consistency, and present a smooth surface which does not crack, chip, nor craze, which is not subject to plastic flow, to printing, to peeling off when subjected `to hot water nor to disintegration by chemically active reagents-but will effectively resist the same and neither absorb nor adsorb water and aqueous solutions.

' While the compositions of this invention are adapted to the coating of metal and other rigid surfaces for protection from water and various chemical solutions to which they might be subjected, comprising for example certain aqueous solutions of inorganic acids, alkalis and salts as well as many organic liquids, theirparticular value is further exemplified in the adhesion, strength, resiliency and flexibility which they impart to cellulosic materials.

A typical surface which presents certain of the conditions above set forth and to which the present invention is particularly applicable is found on the tubes which are employed as supports for the retention of natural and synthetic yarns during the process of purification, dyeing and other fluid treatments ofthe same in package form. A package is comprised of yarn anda support to hold or retain the yarn wound thereon, preparatory to subsequent treatments inthe mill as well as for inspection, shipping to and use of the yarn by the weaver, knitter or other ultimate user, directly from said package. The supports may be constituted of certain metals, of molded thermo-setting resins, of glass or ceramics, or they may be of cellulosic materials impregnated or coated with various materials. 'I'hey may be made in various forms such as springs or in perforated hollow cylinders oi' either plain or congurated design and having either smooth or embossed surfaces. The spring supports are of course hunted to metal construction whereas the perforated hollow cylinders or tubes may be made with other classes of materials as above mentioned.

In the fluid and other treatments of yarn in such package form the supports for the yarn are subjected to various chemical and physical conditions according to the treatment and process employed in treating the yarn. It is therefore necessary that the tubes and surfaces thereof be of such character that they remain substantially unchanged throughout these Various treatments and steps. d

In the normal succession of operations for dyeing yarn in package form, the tubes are mounted on the rotatable spindle of a winding machine and the yarn is wound thereon under controlled tension and usually in cross wind formation and to the desired size or weight. One or more of the thus formed yarn packages are then mounted on a perforated spindle having a diameter slightly less than the inside diameter of the tube. In order to prevent the ow of liquid out at the top of the spindle or between the annular space between the spindle and the tube a tight fitting cap,`having a diameter in excess of that 'of the outside diameter of the tube is secured to the top of the spindle thereby simultaneously sealing the annular opening at the top of the uppermost package as above described and at the same time causing the ends of the other tubes to likewise form a liquid x seal between their respective end surfaces or between circular washers inserted between each of the packages. In order to make these liquid seals tight and fully effective it is necessary to apply considerable axialpressure to the column of tubes through means provided for the same in the design of the cap and of the spindle top. It is therefore a requirement that such tubes shall be capable of withstanding such axial pressure during either dry or wet treatment of the yarn while assembled on the spindles.

' The spindles, containing one or a plurality of such packages, are connected at the base to the delivery side of a pump in a circulatory dyeing system. Treating fluids contained in a lsump or kier, are forced by the pump up into the spindles, radially outward through first the perforations in the spindle and then through those in the tube whence the fluids entei` and ilow through the yarn mass, and back into the kier for subsequent recirculation, continuing until the treatment of the yarn is completed. lIn order to obtain the desired rate of flow of the 'treating liquid through the dense yarn masses it is' necessary to maintain a high pressure on the delivery side of the recirculating pump.' This imposes the requirement on the tubes and coating thereof that they must withstand in the wet state the stresses and strains accompanying such uid pressure.

Certain types of yarn, and more particularly the viscose type of rayon yarn, swell to a considerable extent when wet with aqueous liquids. The connement of the yarn on the tube by the tube itself results in the development of pressure against the surface of the tube imposing a further requirement that the tubes have sufficient wet strength to withstand deformation from this source.

Yarns are commonly dyed with any one of several different classes of dyes each employing in their application various auxiliary chemicals. Representative of these classes are direct, diarotized and developed, acid, vat, naphthol, and sulfur dyes. These and auxiliary chemicals, and approximate concentrations used, together with the conditions of time and temperature at which they may be employed must also be withstood by the dye tubes.

It is therefore a requirement that the composition of this invention and more particularly paper tubes impregnated and coated with the same shall not be substantially deteriorated by the conditions or treatments as -above set forth and that they withstand the stresses and strains set up by shock from alternate hot and cold aqueous baths.

Following the dyeing operation described above, the packages are preferably subjected to centrifugal action by rotating the packages at high speed, whereby the uids held loosely in the interstices of the yarn are thrown o. The remaining water retained by absorption within the fibers of the yarn is afterward removed by drying in an atmosphere of air at elevated temperature and 'low relative humidity. Thus the tubes and coating thereon must be able to withstand the tremendous unbalanced forces imposed upon them in the centrifuging in a wet state as well as to resist becoming brittle and to resist the development of plastic ow and printing during the prolonged heating of the drying process; that is to say, the tendency at the elevated temperature of the dye bath and drying chamber for the coating to soften and the yarn, which swells during the processing, to cut into the coating and embed itself in the surface film during dyeing and drying operations, and become adherent thereto upon cooling. Inspection and Wrapping follow next in order. Practice has demonstrated that the yarn on the individual packages is least disturbed in shipping when they are packed in a horizontal position. It follows therefore that a still further requirement is imposed on such tubes that they must withstand the transverse pressures imposed on them in packing and shipping in cases without appreciable permanent distortion or collapsing.

For reasons of economy it is obviously desirable to provide a perforated tube for the support of yarn in package form which will stand repeated use for the types of dye baths mentioned herein and other fluid treatments of the yarn thereon.

Many metal and molded thermo-setting resins fulll the various requirements set forth above.

However, their cost is high resulting in excessivecapita-l tied up in inventory of tubes. Their much greater weight over that of impregnated paper tubes results in much higher shipping charges per pound of yarn.

It is thus readily seen that the much cheaper and lighter weight impregnated paper tubes are to be preferred provided they are of such character as to withstand repeated use for dyeing and other uid or dry treatments of yarn in package form.

Impregnated or coated, perforated paper base dye tubes heretofore available are not satisfactory for repeated use in dyeing. Some are of low wet strength, some are brittle and shatter in handling and shipping, while some are not resistant to chemicals. But the predominant undesirable feature which makes these tubes unsatisfactory for reuse is associated with their characteristic of dye absorption. During the dyeing operation the dye bath liquor soaks into the tube through the coating and through cracks or pores in the coating. In drying the packages the water from this dye liquor evaporates leaving dry dye dispersed within the tubevstructure. On subsequent reuse for dyeing adiferent shade this dry dye dissolves inthe water during the wettingout step prior to dyeing and that which migrates to the surface of the tube stains the bottom layers of undyed yarn and renders the same unsuitable for use. Attempts to avoid this trouble in other ways as by using a given tube repeatedly for one color only is impractical due to the vast numbers of shades dyed. It is likewise impractical to attempt to sort the emptyltubes upon ,their return from the customer (weaver, knitter,

et aL). Some manufacturers of tubes have attempted to meet this condition with a more thorough coating of the tube with a resinous composition but in `so doing have been confronted with otherundesirable features imparted to the tubes which are associated with the characteristics of the resin itself. That is, in'so doing, the initial water absorption may be very appreciably reduced but the resin coatings are so deficient in having the properties above described.

It is a further and more particular object of the invention to provide a coating composition and coating for cellulosic containers or supports,

such as dye tubes for package dyeing or other fluid treatments of yarn, and the like, which shall withstand or resist the conditions and reagents encountered in dyeing and other fluid treatments of yarn without retaining the Vdye stuff either within or upon its surfaces.

It is also an object to provide a coated tube which maybe used Vand reused in repeated dyeing operations Without regard to the colors of the successive dyes employed and without danger of the dye being retained on or within the tube from one dyeing operation and thereby interfering with subsequent dyeing operations.

It is a further object to provide a coating composition which, when properly applied to a laminated, perforated paper dye tube, will provide a satisfactory dry crushing strength and an improved wet crushing strength, preferably equal to the dry crushing strength of the same tube. It is also an object to provide a resilient tube for dyeing yarn in package form having a smooth, continuous surface which will withstand normal handling without cracking and which will not have sumcient plastic flow to cause printing.

Other more particular obiects with respect to such supports for yarn and the like will appear from the following disclosure.

In accordance with this invention it is found that a new and unique resinous impregnating and coating composition is produced through the separate formation,development, and'subsequent mixing in a mutual solvent, of two distinct types of synthetic resins-namely, alkyd resin (which may be esteriiled and developed in the presence of a drying oil unsaturated acid), and a reactive dialcohol phenol resin, which will be describedk below.

It is also found that the alkyd resin may be prepared in part in the presence of an already prepared, partially condensed, reactive dialcohol phenol resin and that the resulting product while still soluble may be dissolved in admixture with additional solution of a separately prepared reactive dialcohol phenol resin to produce a suitable composition to serve enectively for impregnating and coating in accordance with this invention.

It is further and more particularly discovered as a part of the present invention that compositions as thus formed, are especially adaptable as compositions for the impregnation and coating of resilient materials or surfaces such as cellulosic dye tubes, and present the desirable characteristics indicated above. That is, they are highly satisfactory for application to the vsurfaces and the porous internal structure of firm but resilient substances, to protect the same, and provide a smooth, continuous surface thereon having the combined qualifications and properties which have heretofore been diflicult lif not impossible 40 to secure with cellulosic dye tubes of the prior art. A representative example of the application of the present invention will be described with reference to the impregnation and/or coating of hollow, cylindrical, perforated, cellulosic tubes whichare intended for use as supports for yarn in the dry and iluid treatment of the same in package form. The compositions herein described may be used especially satisfactorily both to impregnate and to coat such nbrous cellulosic dye tubes. On the other hand, it is to be understood that the tubes may be ilrst impregnated with other suitable stiening agents, so long as they impart strength to the tube without making it weak or brittle and without rendering the surfaces of the tube, as thus impregnated, repellant to or undesirably reactive upon the compositions herein described. The compositions of this invention may then be applied to the surfaces of the impregnated dye tube, in accordance with the following disclosure, and will provide a satisfactory surface thereon.

While in general alkyd resins are prepared by the esterication of a polybasic acid with a polyhydric alcohol they are more frequently modified '05 v may be prepared in accordance with the procedure set forth in United States Patent No. 1,800,- 296, dated April 14, 1931, to Herbert Hnel (see Example 17).

While phenolic resins in ,a generic sensefare the condensation products of monohydric phenols with an aldehyde, the phenolic resin of this invention is characterized more particularly as the alkaline condensation product of formaldehyde or paraldehyde with a phenol containing not more than two unsubstituted reactive positions (i. e., the oand p-positions) in the phenyl group. As substituents in such reactive posi-'- tions butyl and amyl radicals are typical and satisfactory, as in p-tertiary butyl phenol and p-tertiary amyl phenol. Suitable compositions of this character may be prepared in accordance with the procedure set forth in United States Patent No. 1,996,069, dated April 2, 1935, to Herbert Hnel (see Example l) 'I'he composition of this invention is prepared by conducting the preparation of the two resin components independently part way, dissolving, and then mixing the still potentially reactive materials in solution. In this condition the resins remain substantially inert over long periods of time. The resin mixture in solvent medium is applied to the material to be impregnated or coated, the solvent removed, and the coated ma- 0 terials heated for sufllcient time and temperature to eifect the reaction of the resin mass until itis converted to the insoluble and infusible state and attains the desired physicaland chemical characteristics.. The time and the temperature to which the mass is subjected in each case will determine the degree of reaction eifected and the properties developed in it but should not be Vso high or so long as to impair the strength of the cellulosic materials of the tube. Increased time or temperature both act independently and collectively to increase the hardness, water irnpermeability, chemical resistance, insolubility,

and resistance to plastic iiow or printing of the resin mass upon subsequent cooling.

It is not possible to prepare any of the mixtures coming within the scope of this invention by mixing the ingredients of the two resin masses in the kettle and preparing it simultaneously. While itis 4possible to chill back the separately and partially reacted alkyd resin with separately and partially reacted pure dialcohol phenol resin and thus simultaneously produce a phenol modifoam excessively and to polymerize too rapidlyduring the required further heating of the partially condensed, low viscosity mixture to effect reaction between the two. Phenolic resins of the dialcohol type modified with other substances,.

however, may be added for the purpose of chilling and arresting the reaction with greater freedom, as will appear below.

The method of the invention-that is, the independent preparation of the two resin components to a certain stage (i. e., with or without addition to the alkyd component) and dissolving in solvent, mixing in the proportion required, application of the resulting composition to the article to be impregnated or coated, followed by solvent removal and completion of the reaction on the coated article by the application of heatmakes it possible to provide a coating and impregnation of cellulosic dye tubes or the like with the desiredvcomposition and properties.

It is further found that the independently prepared resins if used aloneior the purposes of Ithis invention are not satisfactory and have entirely different properties from those produced by mixtures of the two within the limits specified below.

For example, the alkyd resin component may beprepared by esterifying together an oxidizable (unsaturated or drying oil) fatty acid (e. g., 3 parts by weight), phthalic anhydride (e. g., 4; parts by weight), and glycerine (e. g., 2 parts by weight), by heating to 150 to 240 C. and

keeping the reaction mixture at that temperature until the desired Viscosity is obtained. This point may be ascertained by removing from time to time and dissolving a sample of the mixture in a given proportion of solvent and determining the viscosity of the resulting solution.

As soon as the desired point is reached-which must of course be shortl of that at which the reaction product becomes insoluble or produces a 'solution -so viscous as to impede molecular association (e. g., a viscosity of 378 centipoises at 80 F. in a 50% solution in xylol in the above example represents a satisfactory final stage) the temperature is promptly lowered and further development oi' this reaction is arrested. 'I'his may be effected in any convenient manner', as by mechanical cooling, without change in the composition, by admixture with a solvent (in a kettle provided with a reflux condenser), by the addition of chill-back materials such as a rosinmodified dialcohol phenol resin which has been separately prepared, as herein described under III, or by bodied drying oils or by rosin alone.

Substantially any proportion of these compositions may be added. (For example 2 parts of the resin-modified dialcohol phenol resin to 9 parts of the alkyd composition above described.) Pure dialcohol phenol resin may be added at this stage,

but in 'this case the proportion of pure phenolic component ^which can be added to the alkyd resin is limited, and should not exceed 15 parts of the pure phenolic solids to 85 parts of the `alkyd resin, as above mentioned.

The reaction batch of the combined resin components is then pumped into an equal weight of a solvent liquid, such as xylol, hydrogenated naphtha, etc., and dissolved therein.

The unsaturated or drying fatty acid, may be perilla oil or linseed oil acid, which is preferred,

or a mixture of linseed oil acids (2 parts) and China wood oil acids (l part) may be used; also, soya bean oil fatty acid and linseed oil fatty acid alone, as well as certain oxidizable fish oil acids. The fatty acids thus used are characteristically unsaturated, oxidizable acids. While such oxidation is only slight, under conditions of processing `by this invention, it is of suflicient extent to aeraaae able in this respect.. and fatty acids from oils of higher iodine values are preferred.

The product as above obtained (with perilla oil fatty acid) exhibited the following properties: In a solution in xylol, sp. gr. 0.992; acid number 13 to 18, immiscible with oils and varnishes. Bakes to a hard final-condensation product in one-half to two hours at 150 to 250 F. Will tolerate the addition of petroleum solvents (that is, high boiling, aliphatic hydrocarbons), to its solutions, without causing separation, to the extent of about It is quick setting and will dry (with added drier) in the a Separatelxr and apart from suchv modified alkyd resin" composition, or solution of the same,

there is independently prepared a pure phenolic resin, which is free from additions, such as rosin and ester gums, which are sometimes used in products of this type. Pure phenolic resin is a term well known in the trade. Such phenolic resin, suitable for the purpose of the present invention, is produced under the influence of an alkaline catalyst, and may be made and its several properties developed to the required degree in customary ways. Characteristics thereof should be oil solubility, heat hardening, and reactivity with unsaturated oil and resin acids at elevated temperatures.

For example, p-tertiary butyl phenol (e. g., 150 parts by weight) may be mixed with a formaldehyde solution (e. g., parts by weight of a 40% solution) and caustic soda solution (e. g., 75 parts of a 3N solution in lwater) and the mixture maintained at 50,to 551 C. for 24 hours. Then hydrochloric acid (10 parts) is added, whereby the condensation product of the -p-tertiary butyl phenol and formaldehyde is precipitated. The oily condensation product. after being separated from the supernatant water, is condensed further by heating gently for 3 or hours at to 150 C., whereupon it resinifies.

Para-tertiary amyl phenol may be used as a satisfactory substitute for p-tertiary butyl phenol, but higher alkyd substituted phenols are not satisfactory because they form dark-colored products, and are not so mobile or reactive ln the curing process.

Typically, the composition prepared with p-` the other hand this pure phenolic resin alone is insufficiently film-forming, is brittle, of low resistance to abrasion, has low crushing strength and low distensibility and due to the fact that it forms a discontinuous film and cracks readily it will4 permit water'to penetrate readily therethrough if used alone as an impregnant or coating.

- III .The rosin-modied, dialcohol phenol resin constituent of the alkyd resin component, as above mentioned (under I), is separately prepared by esterifymg rosin in the usual way with glycerine (see Ellis Synthetic Resins and Their Plastics,"

Pages 271 to 272, Chemical Catalog Company, Inc., 1923), melting 100 parts of the resultin ester gum with 30 parts of the pure phenolic resin,l prepared as just described (under 1I) at 375 F. until the resin mixture is homogeneous, and then carrying the temperature up to 5254 P., until the formation of foam subsides. The

batch is then allowed to cool down to room temperature, when it is ready for use as above described under I. Upon addition to the alkyd resin itmay react further to some extent to form molecular complexes. u

Neither the straight nor the co-condensed, kettleeprepared, phenol-modified alkyd resin nor the pure phenolic resin is suitable alone for fully carrying out the objects or purposes of this inalkyd resin alonel containing even the maximum phenol formaldehyde ratio which Ican be incorporated and handled successfully by the method of Example I will exhibit the characteristics on dye tubes of good flexibility, and good adhesion By combining the resins prepared as above described and in the proper proportions, in solution, a composition having the desired properties and producing a coating meeting the exacting requirements above set forth is obtained. Thus. in use as a coating on cellulosic tubes for supports in the dyeing and other fluid treatments of yarn in package form such composition is resistant to the penetration of aqueous dye baths, either hot or cold (e. g., at temperatures up to 190 F.)

` whether'neutral, acid or mildly alkaline, unafin the dry state and freedom from printing. Y

However, other predominant characteristics such as low dry and wet crushing strength, high absorption of aqueous liquors, poor alkali resistance and reduced adhesion on prolonged immersion in hot aqueous baths make it unsuitable for use alone for carrying out the objects and purposes of this invention.

'I'he pure dialcohol phenol resin (under Example II) is totally unaffected by dyes, water or even mild acid and alkaline baths. But due tof its extreme brittleness the hardened film on tubes craze badly and chip or flake off. These cracks or craze marks are so extensive that the coating is discontinuous, thereby allowing dye solution and other aqueous liquors to enter the tube. The l dry and wet crushing strengths of cellulosic dye tubes treated therewith are lower than those impregnated with the composition of this invention. The phenolic resin impregnated and coat ed tubes are in fact so lacking in flexibility that many shatter in normal use. the inertness of this resin it likewise is not suit- Thus in spite of able alone for the objects and purposes of this invention.

Attempts to produce baking varnishes by utilizing the desirable features of the phenolic resin and overcoming the brittleness and discontinuity of the resin film by reacting the same in admixture with drying oils, particularly Chinawood oil, also have not met with complete success. The presence of the oils reduce the film strength and impart va tendency to peel upon prolonged immersion. Furthermore thev alkali, water and dye resistance all decrease with increasing proportions of drying oils. It is also difficult to completely oxidize or polymerize all of the drying oils contained within avthick, fibrous structure. This mobile, unoxidized oil tends to sweat to the surface of the tube during dyeing and drying of the yarn which of course spoils the yarn in contact therewith. f

ponents.

fected by oxidizing and reducing baths, and resistant to dyeing by theclasses of dyestufls hereinbefore set forth. Compositions containing approximately 75% to 15% of the modified alkyd resin component and 25% to 85% of thephenol formaldehyde resin component by weight, are found to be satisfactory for the purposes of this invention. Approximately equal proportions exemplify an especially suitable ratio of these com- For example, a specific composition may be composed of '75% of the modified alkyd resin component I dissolved in xylol and 25% of the straight phenol formaldehyde resin component II dissolved in xylol, with the `further addition of xylol to produce a desired viscosity, as follows:

450 parts by weight of the above-described modiiied alkyd resin (I) at 50% concentration in xylol.

parts by weight of the above-described phenol formaldehyde resin (II) at 50% concentration in xylol.

400 parts by weight of xylol.

parts of'resin solids and 700 parts of xylol.

The amount of solvent used may be varied to permit of obtaining a resulting solution of desired consistency for optimum application as an impregnant or as a coating, as the case may be. 'I'he precise amount is not critical. Solvents other than xylol or mixtures of solvents may be used or diluent may be added for the purpose of controlling the volatility, cost, etc., of the solvent media. Care must, of course, be exercised in the use of diluents so as to avoid adding more diluent than' the particular mixture will tolerate; otherwise, the resin is thrown out of solution by the diluent and the solution will become turbid or opaque.

In the preparation of the alkyd resin composition, under I above, instead of chilling back the batch with the rosin-modified phenolic resin as there described, and also instead of the fatty acid, a partly heat-bodied oxidizable oil may be employed. For example, one part of soya. bean oil, or more may be used (V, see below) or 1 to 2 parts of linseed oil (VI, see below) in the formula there given. 'I'he iodine value of linseed oildyeing tube or the like therewith, evaporating the solvent and heating the resulting residual resin mixture, a very satisfactory tube is produced. In such procedure, three reactions may take place during the baking step. In the ilrst case, the pure dialcohol phenol resin may combine to form larger molecules, by condensation with themselves, thus imparting to the film the highest degree of water resistance and greater chemical resistance to alkalies and acids. Or, the dialoohols may combine with the pure alkydresin, so that two hydroxyl groups of one phenolic :resin unit link together two of the resin molecules, thereby forming larger and more inert, chemically and water-resistant molecules. The third reaction is the polymerization of the pure alkyd resin. The degree to which each of these reactions predominates will be determined by the relative proportion of the reagents in the composition. The water resistance. hardness, distensibility, abrasion resistance, and tensile strength will be also aected by the proportions of each of these resins present. Characteristics of the lm containing high proportions of the alkyd resin will be low Water resistance, poor alkali resistance and high distensibility, as already discussed. Likewise, illms containing high proportions of the pure phenolic resin are characterized by brittleness, poor abrasion resistance, and high hydrolysis resistance. A

The solution, as suitably prepared in accordance with the above compositions and procedures, may be applied to some articles in the `usual manner as by spraying, brushing, dipping` or vacuum impregnating. However, inthe application to cellulosic dye tubes or the like it is usually advisable to utilize solutions of the highest solids content at a working viscosity and hence to apply the solution in such a manner that it will replace as far as possible any air contained within the tube structure. This may be done by vacuum impregnation, partial vacuum impregnation or by 4 simple immersion. It has been found that an eflicient and practical method of obtaining a partial vacuum impregnation Without the use of vacuum equipment is obtained by first heating the tubes for the dual purpose of eliminating the natural moisture in the fibers and decreasing the weight of air in the tube through expansion. The tubes While still hot are immersed in a relatively colder impregnating bath whereby the chilling of the hot air in 4the tubes causes a partial vacuum and produces the initial rapid entrance olf the impregnating liquid. More than one treatment may be employed, depending upon the results desired, the condition of the material and surface of the article and the solids content of the impregnating solution. Each application of the composition should be followed by the gnadual elimination of solvent so as to insure a smooth surface film free from blisters, pinholes, etc. The solvent-free coated tubes may then bebaked at a temperature of approximately 250 F. to 300 F. and for a suiiicient time to cause the resin constituents to become insoluble, infusible, print free, 65 hard and resilient.

The resulting product is especially characterized by presenting a continuous, substantially impermeable, impenetrable surface, uniformly and securely attached to the surface of the treated article to which it is applied and. which is also resistant to aqueous dye baths and normally active and reactive aqueous solutions such as hot, neutral, acid, or mildly alkaline solutions. When the material to be treated is permeable or porous, 75

as in the case of cellulosic dye tubes, the liquid i composition penetrates through the surface, enters the interior structure and displaces air and other gases, moisture, etc., contained in the interior of such structures. Moreover, even 1aminated or porous' edges or other surfaces are uniformly coated and rendered impermeable and impenetrable to the dye liquor. Furthermore, the surface of the coating and the coating as a'whole are hard and resistant to becoming plastic or tacky and to "printing by the yarn Wound thereon, even at high temperatures and yarn pressures developed `through swelling of the yarn, but is nevertheless resilient, elastic and tough against structural deformation of the cylinder or of the coating or outer surface and imparts aconsiderable degree of strength thereto. The surface of the coating is smooth and hard so that the winding and dyeing operations neither involve abrasion nor wear of thecoating surface or of the yarn bers.

One form of cellulosic dye tube whch is typical and suitable for treating in accordance with this invention is made of several layers of fibrous sheet material, such as long ber kraft or alpha cellulose paper, formed into a hollow cylinder, for

example, about 11a" thick, 2" in diameter and 6" long, with numerous perforations of about ya" diameter. Such dry untreated tubes weigh about 25 grams each and exhibit a dry crushing strength of about 42 pounds, with no clearly defined point of failure. The treated tubes likewise, upon ultimate crushing, show no clearly deiined point of failure, thus indicating the iiexibility and toughness of the coatings and of the integration of the coatings with `the tubes. Results obtained with such dye tubes by varying the compositions, proportions, and procedures followed are indicated ln the accompanying table in which the first column gives an identifying number for each solution used; the second column the amount of a 50% solution of alkyd resin composition (I) dissolved in xylol and containing perilla as the fatty acid;

column three, the amount of a 50% resin solution, dissolved in xylol, of resin composition (V) (like I, containing no rosin-modied phenolic resin, but bodied soya bean oil instead of it); column four, the amount of a 45% resin solution, dissolved in xylol, of resin composition VI (like No. I containing no rosin-modiiied phenolic resin but bodied linseed oil in place of it) column live, the amount of a 50% solution dissolved in crushing strength; and column eleven, the crushing strength after immersion in water for one hour at F. of the impregnated and coated dye tubes; column twelve, the amount oi' water absorbed by a treated dye tube upon immersion in water at 180 F. for one hour; column thirteen, the effect of dyes to stain the tubes; and column fourteen, the eiect of winding threads on the coated dye tubes to cause printing.

The results indicated that, upon normal drying and ybaking of the tubes at 250 to 300 F. for three hours, as above described, those tubes having a coating containing soya bean oil and linseed oil, instead of perilla oil (solutions 6 to 12 incluby simple immersion. n the other hand, solui tions of very low viscosity usually will not contain a sumcient amount of the resin composition and the relative eillciency-of the coating or impregnation procedure is reduced and too many treatments are required or the tubes are not satisfactorily coated or impregnated. For example, with solutions 1 to 5, a concentration having a viscosity of 6 centipoises was used, while l solutions 6 to 13 were of 20 centipoises.

In actual practice of dyeing yarn upon cellulosi dye tubes treated in accordance withthe invention, various types of dyes have been successfully employed and various procedures followed with satisfactory results in each case.

These may be summarized as follows:

ADirect dyes These may be applied in aqueous baths having pH values ranging from 5 to 8. Dyestuff concentrations vary and run up to 0.7 per cent concentration in the bath. Other chemicals consist mainly of Glaubers salt or common salt in concentrations up to 1.0 per cent in the bath. Dyeing may be made at temperatures varying from to 192 F., and for time periods up to four and 'one-half hours.

After-treatment of direct colors To increase the fastness of certain ldirect colors, an after-treatment comprising 0.2 per cent of acetic acid and 02 per cent formaldehyde in the bath may be employed. This treatment may be carried out up to y F. and for .up to one hour.

Diazotized and developed dyes cent of sulphur dyestuffs at temperatures up tow,

This treatment is likewise similar to that for the application of direct dyes.l Diazotization takes place in a bath containing 0.7 per cent sulfurie acid and 0.35 per cent sodium nitrite. The treatment is usually conducted at about 75 F. for one-half hour.

The diazotized color is further developed on the yarn in an aqueous bath containing' 0.2 per cent soda ash and 0.2 per cent beta naphthol at a temperature of '15 F. and for approximately one-half hour.

Acid dyes This type of dyestui! is usually applied from a boiling aqueous bath containing 0.5 per cent sulfurie acid or formic acid and 1.0 per cent Glaubers salt i'or approximately two to four hours duration. i

Vat dyes This type of dyestui! is applied from an aqueous bath containing about 0.25 per cent sodium hydroxide and 0.25 per cent sodium hydrosulphite or Lykapon to reduce and maintain the dye in the soluble state. This phase of the treatment may be carried out at temperatures up to about F. and for time periods up to about one and on the yarn is oxidized from an aqueous acidied bath usually containing about 0.25 per cent acetic acid and 0.06 per cent potassium chromate. This latter treatment can be carried out at any temperature up to 180 F. and is usually complete in from ten to iifteen minutes.

Naphthol dyes This type of dyestuff is applied from an aqueous bath containing. approximately 0.3 per cent vof dye, after conversion to the corresponding naphthalate, and from 0.5 to 1.6 per cent of sodium hydroxide at temperatures up to 110 F. After rinsing with fresh water, the color is developed in a cold aqueous bath containing up to 0.3 per cent of color salt. Excess or surface dye is removed by a scour in a 1 per cent soap bath.

Sulphur dyes This type of dyestuil' is appliedin an aqueous bath containing up to approximately 0.2 per cent of sodium carbonate (soda ash), 1.0 per cent anhydrous sodium sulfide (commercial chips or equivalent weights of other grades) and 0.7 per F. for time periods up to three hours.

Stripping dye from yarn It is frequently desirable to salvage improperly matched or dyed yarn by stripping a substantial portion of the color already on it. A suitable solution is the aqueous bath containing 0.15

`percent commercial flake caustic soda and 0.15

equivalents which fall within the scope of the` appended claims.

I claim: 1. Method for the preparation of coating compositions resistant .to the operations of dyeing yarn thereon, comprising as steps heating, to

reaction, alkyd. resin reagents, comprising a polycarboxylic acid and a polyhydric alcohol, modifying the same during reaction bya member of the group consisting of unsaturated fatty acids and glycerides of drying and semi-drying oils, separately forming a resin by reacting a phenol containing a substituent of the group consisting of amyl and butyl radicals and havone-half hours. After rinsing, the reduced dye 76 ing not more than two no r less than one of the reactive positions which are ortho and para to vthe hydroxyl in free condition with formaldehyde in the presence of an alkaline catalyst, heat reacting a portion of said unmodified phenollc resin with an ester gum, adding said ester gum modied phenol resin to said alkyd resin while the alkyd resin is still hot, mixing theproduct so formed with Van additional amount of said unmodined phenolic resin in a common solvent to form a composition containing the alkyd and phenol resin components in the proportions of 75% to 15% and 25% to 85%, respectively.

2. The product produced by the method of claim l.

EVEREIT C. ATWELL. 

